OC 45.3 - Non-invasive In Vivo Thrombus Imaging in Patients with Ischaemic Stroke or Transient Ischaemic Attack.

Monday, July 11, 2022

3:15 PM – 3:30 PM

Location: ExCel Center, ICC Capital Suite Room 8&9

Presentation Format: In-Person

Presenting Author(s)

BW

Beth Whittington, MD

BHF Clinical Research Fellow and Cardiology Registrar
University of Edinburgh
Edinburgh, Scotland, United Kingdom

Co-Author(s)

DN

David Newby

British Heart Foundation Duke of Edinburgh Chair of Cardiology
University of Edinburgh
Edinburgh, Scotland, United Kingdom
ET

Evangelos Tzolos

Clinical Research Fellow and Cardiology Registrar
University of Edinburgh
Edinburgh, Scotland, United Kingdom
MW

Michelle Williams

Senior Clinical Lecturer and Consultant Radiologist
University of Edinburgh
Edinburgh, Scotland, United Kingdom
JW

Joanna Wardlaw

Chair of Applied Neuroimaging, Head of Neuroimaging Sciences and Edinburgh Imaging
Univeristy of Edinburgh
Edinburgh, Scotland, United Kingdom
EV

Edwin Van Beek

SINAPSE Chair of Clinical Radiology, Deanery of Clinical Sciences Edinburgh Neuroscience Edinburgh
Unversity of Edinburgh
Edinburgh, Scotland, United Kingdom
RB

Rong Bing

Clinical Research Fellow and Cardiology Registrar
University of Edinburgh
Edinburgh, Scotland, United Kingdom
TC

Tim Clark

Medical Physicist
University of Edinburgh
Edinburgh, Scotland, United Kingdom
CL

Christophe Lucatelli

Senior Radiochemist
University of Edinburgh
Edinburgh, Scotland, United Kingdom
WW

William Whiteley

Reader in Neurology and Consultant Neurologist
University of Edinburgh
Edinburgh, Scotland, United Kingdom
PS

Piotr Slomka

Professor of Medicine and Cardiology, Artificial Intelligence in Medicine, Cedars-Sinai, UCLA
Cedars-Sinai Medical Center
Los Angeles, California, United States
MD

Marc Dweck

Consultant and Chair of Clinical Cardiology at the University of Edinburgh
University of Edinburgh
Edinburgh, Scotland, United Kingdom
AS

Andrew Stephens

Chief Medical Officer
Life Molecular Imaging
Berlin, Berlin, Germany
NK

Norman Koglin

Head of Scientific Operations
Life Molecular Imaging
Berlin, Berlin, Germany

Background: 18F-GP1 is a novel positron-emitting radiotracer that is highly specific for activated platelets and thrombus. It is a small molecule derivative of elarofiban and has a high and specific binding affinity for the activated glycoprotein IIb/IIIa receptor on activated platelets. Preliminary studies using 18F-GP1 demonstrated excellent in vivo binding properties in a range of conditions including left ventricular thrombus following myocardial infarction, pulmonary thromboembolism, deep vein thrombosis and coronary thrombosis.

Aims: In a pilot proof-of-concept study, we aimed to determine its potential clinical application in establishing the role and origin of thrombus in stroke.

Methods: Eleven patients with recent ischaemic stroke (n=9) or transient ischaemic attack (n=2) underwent 18F-GP1 positron emission tomography (PET) and computed tomography (CT) angiography at median of 11 [4-17] days from symptom onset. 18F-GP1 uptake maximum and mean target-to-background ratios (TBR) was assessed in the carotid arteries and brain

Results: 18F-GP1 uptake was identified in 9/11 patients: 5 in the carotid arteries only, 2 in the brain only and 2 in both the brain and carotid arteries. In those with carotid uptake, 4 had >70% stenosis and 3 had non-stenotic disease. One case had bilateral stenotic disease but only the culprit carotid artery showed 18F-GP1 uptake. Overall, uptake was higher in the ipsilateral carotid artery (TBRmax 2.51±0.95, TBR mean 1.75±0.48) compared to the contralateral non-culprit artery (TBRmax 1.66±0.55, TBRmean 0.79±0.20). Four cases showed visual uptake within the brain (TBRmax of 6.63±2.27 and TBRmean 3.73±2.67) corresponding to areas of CT-defined infarction. There was no brain 18F-GP1 uptake in the 7 cases without CT-defined acute cerebral infarction.

Conclusion(s): 18F-GP1 PET-CT is a non-invasive method of identifying in vivo cerebrovascular thrombosis which holds major promise in understanding the role and origin of thrombus in stroke.

Acknowledgments
British Heart Foundation funded this work (RG/16/10/32375, FS/CRTF/21/24129).
Life Molecular Imaging provided reagents for 18F-GP1.